"Briefs" Tab

It could be under the friend and nitro button in DM or the (open) DM button. It has the following features
1) View all messages / post of the channels  the user has followed( which does not need to be announcement and can be any public channel) of all followed channels in all servers in a single page 

2) An option to View all posts on a particular User in all servers you have followed ( the particular user has the option to allow it or not)

3) Filters like viewing only from a particular Server or Particular channel or a particular person(the particular person can allow it or not)